A 15-year-old Allegan County boy was arraigned Thursday afternoon for murder, charged with killing his 21-year-old cousin and attempting to kill his 67-year-old grandmother.

The stabbings occurred while the 21-year-old’s child was asleep in the house. That child was not injured.

“That’s as bad as it gets,” Michigan State Police Lt. Patrick Boyd, commander of the Wayland Post, said outside the Allegan County Courthouse after Joshua Lee Keyzer was arraigned via video by Magistrate Kirby Goodwin.

Both charges could be punished with life in prison. Allegan County does not have any juvenile offenders serving life prison terms.

Keyzer’s parents were in the gallery and did not make a statement. They immediately left with their son’s attorney, Mike McEwen.

Keyzer is being held in the Allegan County Jail without bond.

His preliminary exam is 9 a.m. July 16. A preliminary exam is a court hearing conducted to determine whether enough evidence exists to send a case to trial.

Allegan County Central Dispatch received a 911 call at 12:46 p.m. Wednesday of an assault in progress in Wayland Township on the eastern side of the county, according to the Michigan State Police.

Keyzer was on the roof at the house when police arrived and fell off, then tried to run, Boyd said. Police used a Taser to stop him.

Upon entering the house, police found Keyzer’s grandmother Sharon Keyzer with severe injuries to her neck. She was taken to a Grand Rapids hospital and is expected to recover, Boyd said.

The body of Kassandra Keyzer was found in the lower level of the house.

A knife was discovered at the scene.

Kassandra did not live at the house. She attended Aquinas College, where she worked in the Information Technology department.

Her Facebook page had posts about her brother’s high school graduation and her upcoming wedding in July.

Police do not yet have a motive. An autopsy of the victim was being conducted Thursday.

“There are very unusual circumstances that led to this,” Boyd said.

— The Associated Press contributed to this report. Follow Jim Hayden on Twitter@SentinelJim.